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This paper presents the development of an instrumental prototype for IR hyperspectral imaging from geo-synchronous earth orbit (GEO). Within the framework of collaboration and funding support from the Canadian Space Agency (CSA), Telops performed the development and technical demonstration of a spectral dispersive module (SDM) with potential application for the US NOAA Hyperspectral Environmental Suite (HES). HES development will provide infrared and visible environmental data collection capabilities for the next GOES program series of geo-synchronous satellites that will collect weather and environmental data to aid in the prediction of weather and in climate monitoring. The design of the SDM is based on an Offner configuration. Such a design allows the gathering of high spatial and spectral resolution data while keeping the spatial and spectral distortions smaller than the size of a pixel. A convex diffraction grating is used in the system as a spectrally dispersing element. The targeted application of this Offner spectrometer configuration is weather sounding in the mid-IR spectral range. The design and demonstration phase of the SDM is described. Test results, such as spectral/spatial resolution, distortion, transmission and efficiency, with the engineering laboratory model are presented.

The departure between a reference range image and an acquired one is assessed using correlation. Decision criteria have been defined. Performance of coding and filtering are discussed. Results obtained on a Vander Lugt correlator with two twisted nematic spatial light modulators are given.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A prototype for laser mammography based on a time-domain technique has been developed. The system uses a streak camera and a Titanium:sapphire laser which provides ultrashort pulses at a repetition rate of 80 MHz. A multi-port scanning head which includes optical fibers scans the breast in a point-by-point scanning procedure. Time-resolved transmission is measured at 15000 locations in 7 minutes. The breast is slightly compressed in both the cranio-caudal and the mediolateral projections. Amplitude calibration of the streak camera has been performed allowing for absolute measurement of time- resolved transmission. In addition to the shape of the time-resolved transmission, the absolute amplitude is relevant in properly evaluating the absorption and scattering coefficients. Promising results on solid phantoms and in vivo have been obtained. Both breasts of 10 volunteers have been scanned to date and a larger pilot study is planned in the near future. In addition to the usual time-gating processing, images of the scattering and absorption contributions are also extracted using an original data processing technique.

The use of two optical diagnostic techniques for the visualization of low-gravity experiments is described. The analysis of requirements relevant to the low-gravity environment led to the choice of real-time holographic interferometry and moire deflectometry as suitable optical visualization techniques. An optical setup designed to operate in the KC-135 aircraft is described. An interactive fringe analysis system is also presented. Fringe center lines are extracted using a special onedimensional algorithm. The reconstruction of physical parameters from axisymmetrical objects is achieved using direct and inverse Abel transforms on moire and interferometric fringe fields. The applicability of the optical diagnostic techniques to the visualization of laser processing with liquids and solids in a low-gravity environment is demonstrated and experimental results on laser beam interaction with plastic, quartz, and water are presented.

2 procedures, visual cue fading and task complexity, involved in teaching simple auditory discriminations were investigated. 20 severely retarded children were assigned to 1 of 4 treatment groups in a 2 x 2 factorial design. Analysis of variance on the final day’s data indicated differences favoring visual cue fading procedures and indicated that a 2-stimulus task is much more difficult than a 1-stimulus task. Another analysis of variance showed only differences in task difficulty. The need for further investigations into the variables affecting auditory discrimination is indicated.